Amalgam mixer and separator



Aug 3, 1965 D. THOMPSON 3,198,502

AMALGAM MIXER AND SEPARATOR Filed Jan. l0, 1961 2 Sheets-Sheet 1 Aug. 3, 1965 D. THOMPSON 3,198,502

AMALGAM MIXER AND sEPARAToR Filed Jan. lO, 1961 2 Sheets-Sheet 2 Dona/d Thompson 2 I N VE N TOR.

Y www United States Patent O This invention relates to a machine for mixing of components to produce a mixture of desired component proportions by separation of an excess of one of the cornponents and is more particularly useful for producing amalgam mixtures.

In the compounding of powdered silver and liquid mercury to produce an amalgam mixture for dental purposes, it is not only desirable to sufficiently mix the components .to produce a non-separating mixture but it is also essential to uniformly obtain amalgam mixtures with predetermined proportions of silver and mercury. IIt is also desirable that both of -the above noted objectives be accomplished rapidly and Without a requirement for careful measurement of the silver and mercury components. It is therefore a pri-mary object of this invention to provide a machine which will rapidly and completely produce an amalgam mixture of different predetermined component proportions with a minimum period of time.

Another object of this invention is to provide a machine for mixing amalgam and capable of producing uniformly reproducible Wet, medium or dry mixtures.

An additional object of this invention is to provide an `amalgam mixing machine which will both .mix the amalgam mixture components and separate therefrom the mercury component in excess of a desired proportion in one loperation so as to accomplish the mixing and separation in -a more rapid manner and also thereby avoiding the necessity for careful measurements of the silver and mercury added to the mixing chamber of the machine.

A still further object of this invention is to provide a machine for producing amalgam having a desired proportion of silver and mercury by separating excess mercury from the mixture in one operati-on while salvaging the mercury for future use.

The amalgam mixing and separating machine made in accordance with this invention therefore includes a reciprocating tubular member, the upper portion of which extends above the machine frame so that an amalgam mixing capsule may be carried by the reciprocating tubular member and easily Iremoved therefrom for unloading and reloading purposes. The mixing capsule includes a mixing bore chamber in which a steel ball is loosely mounted for reciprocatory or vibratory movement within the bore whereby the silver and mercury components added to the mixing bore by removal of a cap portion of the capsule, may be physically impounded by the steel ball in order to cause mixing of the components. Separation of the excess mercury from the mixture is accomplished by providing a separator screen at the lower end of the mixing bore through which the excess mercury escapes from a mercury saturated mixture when the reciprocation imparted to the capsule exceeds a prede-ter- -mined frequency. It will therefore be appreciated that by controlling the speed of `a driving motor which is drivingly connected to the reciprocating tube for reciprocation thereof, the frequency of reciprocation imparted to lthe capsule carried by the tube may be varied in order to release from the mixture predetermined quantities of excess mercury necessary to obtain the desired proportions for the amalgam mixture. Accordingly, a rheostat control yand a ltimer control are provided in conjunction with the electric driving motor so that the maximum speed approached may be regulated by the rheostat for obtaining the desired reciprocation frequencies while theV timer may be `set to regulate the duration of the separation period following the mixing period in order to obtain lthe necessary number ofrreciprocation strokes for mixing the desired amalgam mixture. The frame for the machine accordingly is mounted on a shock absorbing pad so as to reduce the vibration incident to the reciprocation imparted to the tubular member. Also, in order to salvage the excess mercury leaving the mixing capsule, the reciprocating tube member includes a passage through which the excess mercury flows. A cup is accordingly mounted by the'machine frame below the reciprocating tube for receiving the excess mercury and has a conduit connected thereto for conducting the excess mercury to a bottle or other container for receiving the mercury.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming la part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGUREy l is a perspective View of the amalgam mixture and separator Vmade in .accordance with this invention.

FIGURE 2 lis a sectional View taken through a plane indicated by section line 2 2 in FIGURE 1.

FIGURE 3 is a sectional View taken through a plane indi-cated by section line 3-3 of FIGURE 1.

FIGURE 4 is a sectional view taken through the amalgam mixing capsule.

FIGURE 5 is a sectional view taken through a plane indicated by section line 5-5 of FIGURE 4.

Referring now Ito the drawings in detail, it will be observed that the amalgam mixing and separating machine which is generally referred to by reference numeral 10 in FIGUR-E 1 is mounted within a fra-me casing 12 hav- Iing sides 14, a front Iside 16 and a top side 18. As seen in FIGURE l, the front side 16 of the casing 12 rotatably mounts a mixture control dial 2t) which cooperates with a scale 22 mounted on the front side 16 of the casing which maybe so calibrated as to indicate settings for obtaining wet, medium and dry amalgam mixtures. Rotatably mounted adjacent to the mixture control d-ial 26 is a timer control dial 24 cooperating with scale 26 mounted on the casing side 16 to set the mixing time that will be necessary in conjunction with the setting ofthe mixture control dial 29 to obtain properly mixed amalgam in the desired proportions of the components. It will also be noted that a reciprocatory assembly generally referred to by reference numeral 28 has an upper portion which projects above the casing 12. The upper portion of the assembly 2S carries thesilver `and mercury components which are mixed in response to reciprocation of the assembly Z8. The upper portion of assembly 2S extends above the casing 12 l'so that the mixture may be unloaded andthe components -reloaded .thereinto. Finally projecting from the bottom `of the side 14 of the casing 12 is a conduit member 3i) which is connected to a liexible hose 32 by means of which the excess mercury may be salvaged. The flexible hose 32 is accordingly connected to a replaceable container for the purpose of receiving therewithin the excess mercury for future use.

Referring now to FGURES 2 and 3 in particular it will be Iobserved that the reciprocatory `assembly 28 includes .a tubular member 34 which is slidably mounted by the casing 12 within spaced nylon sleeve bushing bearings 36 and 38. The slide bearing 36 is mounted within an aperture formed in the ltop side 18 of the casing. The bearing 36 is 'held within the aperture against axial disassembly therefrom by means of the liange 49 thereof and the O-ring member 42. The slide bearing 38 is mounted in axial alignment with the `slide bearing 36 by means of the transverse member 44 which is xed to a pair of parallel posts 46 and 48 suitably connected as by welding to a bottom plate 5t) and t-o the top side 13 a of the casing 12. The slide bearing 38 similar to slide bearing 36 includes a flange portion 52 and O-ring 54 for locking the yslide bearing against axial disassembly. Accordingly, the tubular member 34 may be reciprocated with the upper portion thereof projecting above the slide bearing 36. It will further be observed, that the tubular member 34 forms a vertical outlet passage 56 through which the excess mercury ows. Also, an annular projection 58 is formed within the passage 55 adjacent the upper end thereof for the purpose of seating thereon the removable capsule assembly generally referred to by reference numeral 60. The capsule assembly 60 is retained within the upper portion of the tubular member 34 by means of a removable cap member 62 having a pin and slot connection 64 to the tubular member 34. A spring element 66 is disposed within the cap member 62 and bears against the top of the capsule assembly 60 so as to yieldably maintain it seated against the annular projection 58 in the tubular member 34. The assembly 28 is accordingly constructed to support precisely controlled reciprocation necessary t-o accomplish predictable mixing and mercury separation.

In order to impart reciprocation to the assembly 28, an electric motor 68 is disposed within the casing 12 and suitably bolted to .the bottom plate member S by a plurality of bolt members 70. The motor 68 is accordingly connected to a. suitably balanced crank member 72 having a crank pin 74 connected thereto. A connecting rod 76 is pivotally connected to .the crank pin 74 and retained assembled thereon by the nut 78. The upper end of the connecting rod 76 has a pin 78 connected thereto which rotatably mounts a bearing 30 in order to pivotally connect .the upper end of the connecting rod 76 to the tubular member 34 which is accordingly provided with an outer bearing race 82 fixed to the tubular member by the bolt portion 84 thereof and held thereon in assembled relation by the nut member 86. It will therefore be apparent that the electric motor 68 upon rotation will impart reciprocatory motion to the assembly 28 of a fixed amplitude. The frequency ofthe rceiprocation however will depend upon the rotational speed of the electric motor 68. Also, the number of reciprocatory strokes will depend on .the duration of operation of the electric motor 68.

In order to control the speed of the motor 68, a rheostat -device 88 is provided whereby the motor armature resistance value is controlled in order to control the motor speed. For the specific purposes of the present invention, the motor may be of the type of which the speed may be varied from zero to 8,000 r.p.m. Also electrically connected with the motor is a timer device 90 which operates in a manner well-known to those skilled in the art to shut olf the motor after starting thereof upon elapse of a predetermined period of time which may be set by the control dial 24 which is connected to the shaft 92 of the timer device 90. Also, the rheostat setting of the device 88 for controlling the speed of the motor 68, may be set by the control dial which is connected to the control shaft 94 of the rheostat device 88. It will therefore be apparent that the mixing and separation accomplished by reciprocation of the assembly 2S may be controlled both as to the frequency of the reciprocation by control of the rheostat device 88 through the mixture control dial 20 and for any particular setting of the dial 20 the necessary `time for producing the proper `amalgam mixture may be set on the timer device 90 through the dial 24. inasmuch as the motor 68 imparts reciprocation to the assembly 28, considerable Vibration will be imparted to the casing 12. Accordingly, a vibration dampening rubber cushion 96 is provided beneath the bottom plate member 50 of the casmg.

Referring now to FIGURES 4 and 5 in particular, it will be observed that the Icapsule assembly 60 to which reciprocation is imparted by .the assembly 28 includes a tubular body portion 98 within which the bore 100 is formed which constitutes part of the mixing chamber for the silver and mercury. A removable top member 102 is threadedly received within the upper portion of the body portion 98 and defines therewith a bore .104 of slightly larger diameter than bore constituting an upper portion of the mixing chamber for the amalgam mixture components. The lower end of the bore 100 forms a restricted outlet 106, which outlet 106 is in communication with a separator screen element 108. The separator screen element `108 is held in assembled position by means of a plug member 110 which is inserted into the lower end of the body member 98 within a recess 112 formed therein for such purpose. An outlet passage 114 is formed within the plug member 110 through which the excess mercury passes after being separated. The screen 10S .accomplishes the sparation inasmuch as it will retain a saturated mercury amalgam mixture thereabove up to a predetermined frequency of reciprocation after which the mercury components in excess of a predetermined quantity in the chamber bores will pass through the screen and dow out of the discharge passage 114 into the passage 56 of the tubular member 34. The physical mixing of the amalgam components within the bores 100 yand 104 is accomplished by a steel ball 1l() which will be vibrated between the lower end of the bore 100 as illustrated by solid line in FIGURE 4 and the upper end of `the top member 102. The amalgam mixture may accordingly liow past the steel ball when the ball is in the upper bore 104 and will be squeezed and pounded by lthe ball as it is moved through the lower bore 100 in order to physically break up the silver and mercury components and form the non-separable mixture in response to -reciprocation imparted to the capsule assembly 60 by the reciprocatory assembly 28. The stepped bore construction will therefore provide greater vibratory impact to the ingredients in the mixing chamber at the lower end thereof so as to achieve a controlled and rapid separation of mercury in the downward direction by removal thereof at said lower end through screen 108.

As was hereinbefore indicated, the excess mercury leaving the outlet passage 114 of the capsule assembly 60 and passing into the passage 56 of the tubular member 34 will drop downwardly therethrough and be received within a cup member 118 which is mounted on the bottom plate member 50 in the casing 12 and is disposed below the lower end of the tubular member 34. Accordingly the conduit member 30 is connected to the bottom of the cup member 118 and extends out through the side 14 of the casing 12. Accordingly, .the excess mercury will be conducted from the cup member 118 from which it is collected and pass through .the tiexible hose 32 connected to the conduit member 30 for reception within a container connected to the flexible hose 32. Salvaging of the excess mercury may thereby be accomplished.

From the foregoing description, operation and utility of the invention will be apparent. It will therefore be appreciated by those skilled in the art, that the machine of the present invention is particulraly advantageous inasmuch as it will both mix and separate excess mercury from the mixture as the speed of the driving motor 68 approaches its maximum speed as set by the rheostat device 88 to which .the frequency control dial 20 is connected. Upon reaching the maximum speed, the desired excess of mercury will be separated from the amalgam mixture. The amount of mercury retained within the mixing chamber will accordingly be uniformly duplicated each time the machine is set into operation at the particular rheostat setting of the motor 68. :It has been found for the particular machine hereinbefore described, that the motor when set for 2,000 r.p.m. operation will produce a wet or mercury saturated mixture, 3,000 r.p.m. will produce a medium mixture and 5,000 r.p.m. will produce a relatively dry mixture. As was hereinbefore indicated the `maximum speed lrange for the motor 68 is 8,000 r.p.m. inasmuch as at said speed of 8,000' r.p.m.

all of the mercury would be removed from the mixture. Accordingly, for any particular maximum speedl setting between 2,000 r.p.m. and 8,000 r.p.m., mixing of the amalgam components sucient to produce a mercury saturated mixture occurs when motor speed approaches 2,000 r.p.m. Thereafter, the continued operation produces separation of mercury from the saturated mixture or reduction of its wetness to an extent determined by the maximum speed setting approach. The time setting is correlated .to the maximum speed setting as hereinbefore mentioned so that the `degree of separation to be ultimately obtained with each speed setting may be achieved within a different minimum period `of time associated with each speed setting. The further advantage of the present mixing machine, resides in the fact that the excess mercury may be salvaged for future use. It will also be appreciated that inasmuch as mixing occurs als the motor speeds up to its maximum set speed, the time for mixing may be held to a minimum so that the mixing process maybe accomplished within .an unexpectedly short time.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A machine for mixing and separating amalgam in' one operation comprising a reciprocable tubular member having a passage, drive means operatively connected to said tubular member for imparting reciprocation thereto increasing in frequency to a preselected maximum, impact chamber means carried by said tubular member containing ingredients, restricted discharge means mounted in said impact chamber means for communication with said passage, means mounted in said discharge means for retaining said ingredients within said chamber means while being mixed by said reciprocation below a predetermined frequency, timing means operatively connected to said drive means for preselecting an operational period during which the reciprocation of the tubular member increases in frequency 'beyond said predetermined frequency to said preselected maximum frequency necessary to obtain removal of an excess of one of said mixture ingredients from the chamber means through the restricted discharge means, and collection means operatively mounted with respect to said passage means in the tubular member for conducting said excess of said one ingredient exteriorly of said machine, said tubular member including an upper portion containing said impact chamber means and a lower conduit portion through which the passage extends, inwardly projecting means maintaining the impact chamber means within the upper chamber portion and an impact element in the impact chamber means of such size as to prevent said one ingredient from freely liowing past the same into the restricted discharge means.

2. A machine for mixing and separating amalgam in one operation comprising a reciprocable tubular member having a passage, drive means operatviely connected to said tubular member for imparting reciprocation thereto increasing in frequency to a preselected maximum, impact chamber means carried by said tubular member containing ingredients mixed during reciprocation, restricted discharge means mounted in said impact chamber means for communication with said passage, means mounted in the discharge means for retaining said ingredients within said chamber means below a predetermined frequency of reciprocation of the tubular member, timing means operatively connected to said drive means for preselecting an operational period during which the reciprocation increases in frequency beyond said predetermined frequency to said preselected maximum frequency necessary to obtain removal of an excess of one of said mixture ingredients from the chamber means through the restricted discharge means and the passage reducing the wetness of said mixture by a predetermined amount, said tubular member including an upper portion containing said impact chamber means and a lower conduit portion through which the passage extends, inwardly projecting means maintaining the impact chamber means within the upper chamber portion and an impact element in the impact chamber means of such size as to prevent said one ingredient from freely flowing past the same into the restricted discharge means.

3. The combination of claim 1 including electric motor means drivingly connected to the tubular member and to the timer means for control of the duration of motor operation, and speed control means operatively connected to the motor means for regulating the maximum speed thereof for frequency control of the tubular member.

4. The combination of claim 3, wherein said tubular member includes slide means having a fixed displacement amplitude, removable cap means mounted on an upper end of the slide means for yieldably engaging the chamber means for yieldably limiting displacement thereof in one direction, said inwardly projecting means limiting displacement of the chamber means in the other direction within the upper portion of the tubular member.

5. The combination of claim 4, wherein said collection means includes, stationary cup means below the tubular member for receiving the excess of said one ingredient from the conduit portion, and conduit means connected to the cup means for conducting the excess of said one ingredient exteriorly of the machine.

6. The combination of claim 5, wherein said chamber means comprises a cylindrical capsule having a mixing chamber bore with a restricted outlet at one end in-communication with said discharge means and closed at an opposite end by a removable top through which said ingredients are added, said impact element being loosely itted within said chamber bore for vibratory movement therein in response to reciprocation of the capsule, said chamber bore including a large diameter portion at said opposite end.

7. The combination of claim 6, wherein said means retaining the ingredients within the chamber means comprises a separator screen and a plug holding the screen in assembled relation with the chamber means and defining a restricted passage therefrom.

8. The combination of claim 1, wherein said collection means includes, stationary cup means mounted below the tubular member for receiving the excess of said one ingredient from the conduit portion and conduit means connected to the cup means for conducting the excess of said one ingredient exteriorly of the machine.

References Cited by the Examiner UNITED STATES PATENTS 1,486,266 3/ 24 Rosenblatt.

2,458,692 1/ 49 Downer.

2,541,043 2/51 Curry.

2,647,638 8/53 Shore 210--388 MORRIS O. WOLK, Primary Examiner.

LEO QUACKENBUSH, JAMES H. TAYMAN, JR.,

Examiners. 

1. A MACHINE FOR MIXING AND SEPARATING AMALGAM IN ONE OPERATION COMPRISING A RECIPROCABLE TUBULAR MEMBER HAVING A PASSAGE, DRIVE MEANS OPERATIVELY CONNECTED TO SAID TUBULAR MEMBER FOR IMPARTING RECIPROCATION THERETO INCREASING IN FREQUENCY TO A PRESELECTED MAXIMUM, IMPACT CHAMBER MEANS CARRIED BY SAID TUBULAR MEMBER CONTAINING INGREDIENTS, RESTRICTED DISCHARGE MEANS MOUNTED IN SAID IMPACT CHAMBER MEANS FOR COMMUNICATION WITH SAID PASSAGE, MEANS MOUNTED IN SAID DISCHARGE MEANS FOR RETAINING SAID INGREDIENTS WITHIN SAID CHAMBER MEANS WHILE BEING MIXED BY SAID RECIPROCATION BELOW A PREDETERMINED FREQUENCY, TIMING MEANS OPERATIVELY CONNECTED TO SAID DRIVE MEANS FOR PRESELECTING AN OPERTIONAL PERIOD DURING WHICH THE RECIPROCATION OF THE TUBULAR MEMBER INCREASES IN FREQUENCY BEYOND SAID PREDETERMINED FREQUENCY TO SAID PRESELECTED MAXIMUM FREQUENCY NECESSARY TO OBTAIN REMOVAL OF AN EXCESS OF ONE OF SAID MIXTURE INGREDIENTS FROM THE CHAMBER MEANS THROUGH THE RESTRICTED DISCHARGE MEANS, AND COLLECTION MEANS OPERATIVELY MOUNTED WITH RESPECT TO SAID PASSAGE MEANS IN THE TUBULAR MEMBER FOR CONDUCTING SAID EXCESS OF SAID ONE INGREDIENT EXTERIORLY OF SAID MACHINE, SAID TUBULAR MEMBER INCLUDING AN UPPER PORTION CONTAINING SAID IMPACT CHAMBER MEANS AND A LOWER CONDUIT PORTION THROUGH WHICH THE PASSAGE EXTENDS, INWARDLY PROJECTING MEANS MAINTAINING THE IMPACT CHAMBER MEANS WITHIN THE UPPER CHAMBER PORTION AND AN IMPACT ELEMENT IN THE IMPACT CHAMBER MEANS OF SUCH SIZE AS TO PREVENT SAID ONE INGREDIENT FROM FREELY FLOWING PAST THE SAME INTO THE RESTRICTED DISCHARGE MEANS. 